Many functional thin films are practically used in the fields of semiconductor devices, displays and luminescent elements. Functional thin films are ones formed by disposing a material having a desired property at desired positions, followed by patterning. The functional thin films are used as wiring, electrodes, insulating layers, luminescence layers, optical thin films, etc.
For example, a photoresist pattern obtained by photolithography may be mentioned. However, process steps of the photolithography are complex, and utilization efficiency of energy, material, etc. is low. Further, there is a problem such that since the photolithography is carried out in a clean room, cost of facilities is expensive.
Specifically, as a method to solve the problems in the photolithography, an ink-jet print method has been proposed. However, in the ink-jet print method, position accuracy is low, and it is difficult to form a fine pattern. Under the circumstance, the following methods (1) and (2) have been proposes to improve the position accuracy by preliminarily forming on a substrate surface a base film having a water repellent region which repels ink and a hydrophilic region which accepts ink.
(1) As a method for forming a hydrophilic region and a water repellent region on a substrate surface, a method may be mentioned wherein a hydrophilic surface is coated with a water repellent material such as a fluorine containing silane coupling agent to form a water repellent thin film, and the water repellent material is decomposed by light irradiation and removed (Patent Document 1). In the substrate obtained by the above method, only a region irradiated with light can be made a hydrophilic surface.
(2) As a method of using ultraviolet ray having a long wavelength, known is such a method that by using a photocatalyst such as titanium oxide, a water repellent thin film is decomposed (Patent Document 2).
Patent Document 1: JP-A-2000-282240
Patent Document 2: JP-A-11-344804